Protective device



Feb. 23 1926.

N. A. LOUGEE PROTECTIVE DEVICE Original Filed Feb. '7, 1918 .7 Hr e zwwmm to t T A VA \\\\\\\\\\\0 I Q m 1 U4 w b m N WV @L M w v l atented Feb.23, 1926.

UNITED STATES PATENT OFFICE.

NORMAN A. LOUGEE, OF SOHENECTADY, NEW YORK, ASSIGNOR TO GENEBAL ELECTRICCOMPANY, CORPORATION OF NEW YORK.

PROTECTIVE DEVICE.

Application filed February 7, 1918, Serial No. 215,796. Renewed November24, 1823. i

T all whom it may concern:

Be it known that I, NORMAN A. Loosen, a citizen of the United States,residing at Schenectady, county of Schenectady, State of N ew York, haveinvented certain new and. useful Improvements in Protective Devices, ofwhich the following is a specification.

My invention relates to protective devices and especially to lightningarr-esters and similar devices which are .operative to remove abnormalpotentials, surges and similar discharges from an electric conductor.

The object of my invention is to provide a simple and durable lightningarrester of the type which is operative to permit a free discharge ofelectricity as long as the difference of potentialbetween the terminalsof the device exceeds a' predetermined. amount but will interrupt thedischarge the instant the difference of potential becomes normal.

More particularly the object of my invention is to provide an arresterof this type which is of unit construction, each arrester comprising aplurality of discharge units, any

number of which may be easily and quickly assembled to provide acomposite arrester for the protection of a conductor under any operatingvoltage and in general provide an arrester which is an improvement onthat covered by the U. S. Patent 1,238,660, granted to Crosby FieldFrank.

The novel features which I believe to be characteristic of my inventionwill be definitely indicated in the claims appended her-c to, while thefeatures of construction and the method of operation will be understoodby reference to the following description taken in connection with theaccompanying drawing which shows the preferred embodiment of myinvention and in which Figure 1 is a side elevation of a protectivedevice embodyin my invention; Fig. 2 is a sectional View o one of thedischarge units comprising my protective device, and Fig. 3 is aperspective view of a discharge unit with one electrode removed.

My protective device is of unitary con struction, as shown in Fig. 1 andcomprises a plurality of discharge units or cells 1, assembled one abovethe other in stack formation, the number of cells depending on thevoltage of the conductor to be protected. It is understood that insteadof mounting the units one above the other, these units may be mountedside by side if desired. Each discharge unit 1, comprises two conductingplates or electrodes 2 and 3, separated by an insulating spacer ormember 4:, which engages the edges of the electrodes to formtherebetween a closed chamber or com artment. In the preferredembodiment 0 my invention, the insulating spacer 4 is circular orring-shaped in configuration and provided with a recessed outer edge 5,as best shown in Fig. 2. This outer edge 5 is preferably glazed toprevent accumulation of .dust or other foreign particles. The electrodemembers 2 and 3 are also preferably in the form of circular plates ordiscs, but it is understood that the spacing member and electrodes maydhave any convenient configuration -desire The electrodes 2 and 3 aresecured to the insulating spacer member or ring 4 and integrally relatedtherewith, in any suitable manner, but in the preferred construction Iprovide the integral relation by crimping or spinning the plateelectrodes over the recessed edge 5 of the spaci member 4, as best shownin Fig. 2, to fbrm thereby a water-tight and weather-proof unit. Inorder to insure a tight joint between the plates and the spacing member4:, I provide a washer or gasket member 6. between the plates 2 and 3and the spacer 4. This gas ket'member 6 conforms with the configurationof the spacer 4 and in the construction shown, consists of a thinannular ring preferably of paper impregated with varnish or othersuitable material. The electrodes 2 and 3 may be made -of brass or othernoncoating process known as sherardizing and v set forth in U. S. patentto Collins and* Capp, No. 1,169,529, January 25, 1916.

\Vithin the compartment or chamber formed between the electrodes 2 and 3is a filler 7 composed wholly or'in part of lead peroxide and preferablyin the form of a powder which constitutes the discharge path between theelectrodes. In order to concentrate to a restricted area, the energy ofa discharge from the electrodes to the filler 7, I provide between thesurface of the filler and either or both the electrodes, a thininsulating layer or film 8, which I preferably lead peroxide, and thenspinning t means, to uprig t supportin washed, after which they aredipped 1n a solution ,of varnish to provide an insulating film of eventhickness on both sides of the plates. The discharge units are thenassembled by spinning or suitable crimping on one of the plates or.electrodes to the spacer member 4 with its gasket member 6,

with

e remaining electrode on the spacer 4 with its gasket member. Theassembled and integrally related units are finally sand blasted toremove the varnish film from the outer filling thespace within thespacer ring or surface portions of both electrodes 2 and.

As best shown in Fig. 1, a protective device for the protection of aconductor opcrating under any voltage may beobtained by merelyassembling the required number of units 1, these units being simplymounted with their electrodes 2 and 3 in surface or contact engagement,preferably one on to of the other to form a stack. If a consi erablenumber of these units are required, I maintain the stack rigid andenable the building up of the arrester to any height desired, by placingmetal or conducting platesv 9 at suitable intervals between the unitsand securin these plates, bysuitable 10 of wood or other ins ating'material which are, in turn secured to base and to members 11 and 12respectively. ith this preferred construction, I am 'able to s ace theupright mem bers 10 away from t e cellstack to permit more coolingaction. It is understood, however, that in some cases I may do away withthe plates 9 and arrange the upright members 10 to engage the outeredges of the units to form a supporting means or rack for the stack.

1 The base and top members are preferably of conducting material andserve as termi-- nals for the arrester, the base -member 11 beingadapted to be connected to round. The top plate or terminal 12 mayconnected directly to the conductor to'be protected, bntin the preferredconstruction I 7 connect the terminal to the conductor through anadjustable spark gap comprising an arcing electrode 13, which is inconductive relation' with the terminal member and carried therebcymembers and a cooperating. arcing electrode 14 a apted to be connectedto the conductor and a so supportedby the terminal member 12 butinsulated therefrom.

-Mounted upon the upright members 10 are protecting or petticoat members15 whic serve to protect the cell units from weather conditions. Eachpetticoat may be of unitar construction, but in the preferredconstructlon these petticoats comprise a plurality of similar shapedportions which are secured together and to each pair of upright members10. There is also provided a hood member 16 supported by the top member12 whichcooperates with the petrotect the cell units course, it is underticoat members 15 to from the weather. 0

stood that the petticoat members 15 and protecting hood 16 are used onlon the outdoor type of arrester, the in oor type having these membersremoved.

Theioperation of my protective device .may be'briefiy described asfollows: When abnormal voltage conditions occur on the conductor to beprotected sufficient to discharge across the gap comprising arcingelectrodes 13-and 14:, a path of low resistance trode l3' tothe topmember or terminal 12, and then by electrode 2 of the top unit throughits filler 7 to electrode 3 and thence to electrode 2 of .the nextadjacent unit which is in contact engagement with the electrode 3 of theunit above and in the same manner through the plurality of units inseries comprising the stack and finally to base member or terminal '11and thence to ground. Due to the insulating film 8 on the electrodes,the. energy of the discharge is concentrated on, a limited .areaof theelectrode' and as the'lead peroxide comprising is provided to'groundfrom the arcing electhe filler and discharge path through each unit is'apoor conductor of heat, a discharge causes, at the point of dischar e, avery local and very intense heating w ich instantly changes a very smallamount of the lead peroxide into a. lower oxideo flead having a veryhigh electrical resistance. As a result of this great'change in' theelectrical resistance of that art of the filler comprising the ath ofd1scharge,-a small mass of substantially non-conducting materialinstantly forms in the ath of discharge sufii-- cient to prevent furt erflow of current at that point. In this manner the arrester permits aready and quickdischarge of current from the conductor and automaticallycuts off the current after the discharge has passed to ground. The gasliberated by'the reductionof the high leadoxide finds its way out of theunits at points between the conducting plates and the spacers-4. Asecond dis charge may occur at some other point on the electrodesconverting the low resistance lead peroxide to a high resistance loweroxide to cut oil. the current. As the area of the dis-.

charge is very small, the electrodes are of suflicient area to permitiagreat'number of discharges to occur before the units need to be renewed.In view of the fact that the quantity of high resistance oxide formed atthe time the arrester cuts off the dynamic current will, in manyinstances, depend upon the voltage of the dynamic current, theresistancewhich the mass of oxide formed by the discharge will offer toa second dis= charge will also be dependent upon the voltage of thedynamic current. As this resistance may not be sufficient to prevent asecond discharge, due to high potential impressed across the unit, suchsecond discharge may follow practically the same path through the unitasthe first discharge.

With the units of the arrester of the construction described, such unitscan be easily and quickly assembled and kept in stock without fear ofdeterioration and when it is desired to assemble an arrester, it is onlyi necessary to place therequisite number of units one on top'of theother in the supporting structure, or with equal facility an arrestermay be disassembled and old units replaced with new ones.

In accordance withthe provisions of the patent statutes, I havedescribed the princi 1e of operation ofmy invention, together with theapparatus which I now consider to represent the bestembodiment thereof;but I desire to have it understood that the apparatus shown is onlyillustrative, and

that the invention can be carried out by other means. 7

.What I claim as new and desire to secure by Letters Patent of theUnited States, 1s,-

1. A protective unit comprising a pairof conducting plates, aninsulatmgmeans be-.

.material within said chamber having 'low electrical resistanceandadapted to be converted' into a material of high electrical re,sistanceby the passage of an electric .dis-' charge thercthrough, andan insulating film upon the inner surface-of one of said plates adaptedto break down locally to permit a local dischar' e throu h saidmaterial, the

' arrangement eing sue that said conductive plates constitute theelectrodes which conduct current into the unit whereby a plate mayeither engage a suitable conductive support or support and makeelectrical contact with another unit.

2. .A protective. device comprising two electrodes, means for s acingthe same apart and insulating them rom one another, one of saidelectrodes having a conductive 0on tact surface designed to makeelectrical con- ..tact with a suitable support and the other of spacingthe electrodes apart and insulating them from one another, one of saidelectrodes forming a portion of the walls of said con-- tainer andarranged to constitute means whereby said.- device may rest against andthus be electrically connected to a suitable support, and materialbetween said electrodes of low electrical resistance, said materialbeing adapted to be converted into material of high electricalresistance by the passage of an electric discharge therethrough.

4. A protective device comprising two parallel plate electrodes, aninsulating spacer between said electrodes, said electrodes .beinginterlocked with said spacer,

and a filler containing lead peroxide between V said electrodes.

5. A protective device comprising a receptacle having a side wall ofinsulating material, electrodes interlocked with said insulating sidewall to form ends for said'receptacle, and a filler composed of materialhaving low electrical resistance,-which material is adapted to belocally converted by heat into a material of high resistance.

6. A rotective device comprising a spacer o insulating material, metalplates cooperating with said spacer to form a receptacle 'andmechanically interlocked at their edges with said spacer so as to beinsulated rom each other, each of said plateshavin face t erect, and afiller between the plates composed of fluent material having a lowresistance and adapted to be changed locally by heat to material of highresistance.

7. A rotective device comprising parallel vmetal p ates each having aninsulating film on its inner surface, a spacer of vitreous ma-- terialhaving a groove in the outer edge. i

lates being crimped into said groove to said plate:

yielding packing between said plates and said spacer, the edges of saidtosaid. spacer, and a .filler between said "plates formed of materialhaving low electrical resistance, which material is adapted to bequickly converted locally into a material of high resistance by anelectrical discharge therethrough.

8. A protective device comprising a receptacle with aside wall ofporcelain havan insulating film on the inner sur- I ing a groove in theouter edge, metal end walls with their edges crim ed into the groove inthe porcelain side wa l to interlock the end walls and the porcelainside wall to form a unitary receptacle, each metal end wall having aninsulating film on its inner surface only, a gasket between eachelectrode and said side Walls, and a fillercontaining lead peroxide forsaid receptacle.

9. A protective device comprising a plurality of disc units, eachcomprising two parallel disc electrodes separated by an insulatingspacer interlocked with said electrodes and a filler containing leadperoxide between said electrodes, each electrode having a conductingouter surface and an in sulating film on an inner surface,-said unitsbeing mounted in a cylindrical stack'with their outer surfaces inelectrical contact.

10. A protective device comprising a plurality of disc units eachcomprising two disc electrodes separated by a spacer and having betweenthem a filler containing lead peroxide, said units being mounted to forma cylindrical stack, a metal plate interleaved between two of said unitsat an intermediate point of the stack to support the units above saidplate and an insulating support for said plate.

11. A discharge unit for a protective device comprising an insulatingring having a recessed outer edge, conducting members on each side ofsaid ring crimped overthe edges thereof to form an integral-structure, afiller containing lead peroxide between said mem bers, and an insulatingfilm between said filler and said members.

12. A protective device comprising a plurality of separate dischargeunits, each unit comprising cooperating plate electrodes, and

' a filling between said electrodes containing lead peroxide, said unitsbeing assembled with their electrodes adjacent and in electricalconnection, supporting means for said units, and conducting membersmounted at intervals between said units operative to hold said units inalignment.

' 13. A protective device comprising a. plurality of separate dischargeunits, each unit comprising a spacer of insulating material and a pairof conductive plates individually secured to said spacer, and a fillingbetween said electrodes containing lead peroxide, said units beingassembled with their electrodes in electrical connection, a supportingstructure for said units including members spaced longitudinally fromthe edges of said units, and conductive means carried by said membersfor maintaining said units in alignment. 1

14. A protective device comprising a plurality of separate dischargeunits arranged in alignment, each unit comprising a spacer of insulatingmaterial and a pair of conductive plates individually secured to saidspacer, and a filling between said electrodes containing lead peroxide,said units being assembled with their electrodes in electricalconnection, a supporting structure for said units including supportingmembers arranged alongside said units and spaced therefrom, conductivemeans carried by said supporting members for maintaining said units inalignment, and petticoat members spaced along and secured to saidsupporting members to protect said units from the weather.

15. In a device of the character described, a series of protective unitsarranged in a pile and means for protecting said units rom the weathercomprising a series of spaced overlapping petticoat members surroundingsaid pile of units.

16. In a device of the character described, a series of protective unitsarranged one above the other, a plurality of overlapping, spacedpetticoat members for shielding said units from the weather, and aplurality of upright members for holding said units and said petticoatmembers in proper alinement. 17. In a device of the character described,a plurality of similar protective units stacked one above the other in acolumn, a plurality of upright insulation members for maintaining saidcolumn rigid, a plurality of spaced overlapping petticoat memberssurrounding said column and secured to said upright members and a capcovering the top of said column.

In witness whereof, I have hereunto set my hand this 5th day ofFebruary, 1918. NORMAN A. LOUGEE.

